In: Statistics and Probability
=
Solution :
Given that ,
mean = = 355
standard deviation = = 80
n = 48
= 355
= / n= 80 / 48=11.55
P(340< <360 ) = P[(340-355) /11.55 < ( - ) / < (360-355) /11.5 )]
= P(-1.30< Z <0.43 )
= P(Z <0.43 ) - P(Z <-1.30 )
Using z table
=0.6664-0.0968
=0.5696
probability= 0.5696